# preset that will enable clang/clang++ with support for MPI and OpenMP (on Linux boxes)

# prefer flang over gfortran, if available
find_program(CLANG_FORTRAN NAMES flang-new flang gfortran f95)
set(ENV{OMPI_FC} ${CLANG_FORTRAN})
get_filename_component(_tmp_fc ${CLANG_FORTRAN} NAME)
if ((_tmp_fc STREQUAL "flang") OR (_tmp_fc STREQUAL "flang-new"))
  set(FC_STD_VERSION "-std=f2018")
  set(BUILD_MPI OFF)
else()
  set(FC_STD_VERSION "-std=f2003")
endif()

set(CMAKE_CXX_COMPILER "clang++" CACHE STRING "" FORCE)
set(CMAKE_C_COMPILER "clang" CACHE STRING "" FORCE)
set(CMAKE_Fortran_COMPILER ${CLANG_FORTRAN} CACHE STRING "" FORCE)
set(CMAKE_CXX_FLAGS_DEBUG "-Wall -Wextra -g" CACHE STRING "" FORCE)
set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-Wall -Wextra -g -O2 -DNDEBUG" CACHE STRING "" FORCE)
set(CMAKE_CXX_FLAGS_RELEASE "-O3 -DNDEBUG" CACHE STRING "" FORCE)
set(CMAKE_Fortran_FLAGS_DEBUG "-Wall -Wextra -g ${FC_STD_VERSION}" CACHE STRING "" FORCE)
set(CMAKE_Fortran_FLAGS_RELWITHDEBINFO "-Wall -Wextra -g -O2 -DNDEBUG ${FC_STD_VERSION}" CACHE STRING "" FORCE)
set(CMAKE_Fortran_FLAGS_RELEASE "-O3 -DNDEBUG ${FC_STD_VERSION}" CACHE STRING "" FORCE)
set(CMAKE_C_FLAGS_DEBUG "-Wall -Wextra -g" CACHE STRING "" FORCE)
set(CMAKE_C_FLAGS_RELWITHDEBINFO "-Wall -Wextra -g -O2 -DNDEBUG" CACHE STRING "" FORCE)
set(CMAKE_C_FLAGS_RELEASE "-O3 -DNDEBUG" CACHE STRING "" FORCE)

set(MPI_CXX "clang++" CACHE STRING "" FORCE)
set(MPI_CXX_COMPILER "mpicxx" CACHE STRING "" FORCE)

unset(HAVE_OMP_H_INCLUDE CACHE)
